Investigation of pollen morphology and viability of sweet and sour cherry genotypes by multivariate analysis.

The aim of this study was to examine the dimensions and surface morphology of pollen grains of some sweet and sour cherry genotypes through scanning electron microscopy (SEM) as an additional alternative identification tool. In vitro pollen germination and pollen tube length as indicators of their viability were determined as well. Observations were carried on 10 sweet cherry (Prunus avium L.) and 7 sour cherry (Prunus cerasus L.) genotypes. All genotypes had prolate, tricolpate pollen grains, and striate exine ornamentation, with more parallel longitudinal ridges. Significant differences among genotypes within species and between species were found for most pollen grain characteristics and exine ornamentation. In both sweet and sour cherry the largest variability was recorded for colpus length (CV = 15.0% and 12.9%, respectively). For sweet cherry genotypes, in vitro pollen germination and pollen tube length ranged between 1.4% to 51.5% and 360.4 to 669.3 µm respectively, while for sour cherries they ranged from 15.5% to 37.0% and 96.3 to 960.2 µm, respectively. The results of the correlation analysis showed that in vitro pollen germination correlated positively with pollen length/pollen width (L/W) ratio (r = .640) and furrow width (r = .588), and negatively with the number of ridges (r = -.517), while pollen tube length was not significantly correlated with any of the studied characteristics. Principal component analysis (PCA) revealed that pollen length, pollen width, L/W ratio, colpus length, mesocolpium width, and ridge width are relevant tools to discriminate among the studied genotypes. The measurements made on pollen grains did not reveal individually big differences, but when all features were considered together, the pollen of each genotype exhibited a unique pattern. The distribution on the scatter plot showed considerable variation among sweet and sour cherry genotypes based on pollen morphological characteristics, which led to their distribution into two separate groups. This demonstrates the ability to distinguish cherry species based on pollen morphological characteristics determined by SEM. To improve discriminative ability for genotypes within species combination between pollen ultrastructural analysis, morphological and molecular markers is desirable, in subsequent work. RESEARCH HIGHLIGHTS: Significant differences in pollen characteristics between sweet and sour cherry. Significance of pollen morphology in taxonomic differentiation. Significance of SEM studies for the taxonomic identification.

The Effect of Different Temperatures on the Viability and Senescence of Plum Ovules (Prunus domestica L.).

This paper reports on a study investigating the viability and senescence of plum ovules when exposed to different constant temperatures over two years. The research was conducted on the primary and secondary ovules of four plum cultivars: 'Mallard', 'Edda', 'Jubileum', and 'Reeves'. The results show that the first indication of ovule viability loss was callose accumulation, which was detected using the fluorescent dye aniline blue. All cultivars had viable ovules, in different percentages, at 8 °C on the twelfth day after anthesis. However, at higher temperatures, distinct patterns emerged, indicating the adaptability of each cultivar at certain temperatures. The first indication of callose accumulation became visible at the chalazal pole. After anthesis, the ovule's ability to remain viable gradually reduced, followed by callose deposition throughout the ovary. The cultivars 'Edda' and 'Reeves', from 6 days after anthesis onward, in both years, showed the highest percentage of nonviable ovules. In contrast, the 'Jubileum' cultivar demonstrated the highest percentage of viable ovules. The loss of viability of secondary ovules followed a similar pattern to that of the primary ovules in all cultivars. This research provides valuable insights into embryological processes, which can help in the following breeding programs, and to cultivate plum cultivars in Western Norway's climate conditions.

Viability of Embryo Sacs and Fruit Set in Different Plum (Prunus domestica L.) Cultivars Grown under Norwegian Climatic Conditions.

Compatibility and synchrony between specialized tissues of the pistil, female gametophytes and male gametophytes, are necessary for successful pollination, fertilization, and fruit set in angiosperms. The aim of the present work was to study the development and viability of embryo sacs, as well as fertilization success, in relation to the fruit set of the cultivars 'Mallard', 'Edda', 'Jubileum', and 'Reeves', under specific Norwegian climatic conditions. Emasculated, unpollinated, and open-pollinated flowers were collected at the beginning of flowering, and on the 3rd, 6th, 9th, and 12th days after flowering, from all four plum cultivars over two years (2018/2019). Ovaries were dehydrated, embedded in paraffin wax, sectioned, stained, and observed under a light microscope. Results showed the existence of synchronization between successive phases in the development of the embryo sac and individual phases of flowering. All plum cultivars had higher percentages of viable embryo sacs, fertilized embryo sacs, and fruit set in 2018 than in 2019. These differences may be related to the very low temperatures during the post-full-flowering period in 2019, and to the low adaptation of some studied cultivars to unfavorable conditions. In our study, the cultivar 'Jubileum' showed the highest percentage of viable embryo sacs, fertilized embryo sacs, and fruit set compared to other cultivars, i.e., the best low-temperature adaptation.

Functionality of Embryo Sacs in Pear Cultivars 'Ingeborg' and 'Celina' as Related to Fruit Set under Nordic Climate.

Since the European pear (Pyrus communis L.) is a self-incompatible fruit species, synchrony and compatibility between female parts of the mother plant and male gametes from the pollen donor must be fulfilled. Besides pollination and fertilization, normal embryo and zygote development is one of the prerequisites for the satisfactory yields in pears. The main goal of this experiment was to investigate the functionality of embryo sacs and the embryo's early stages of growth in relation to the fruit set of diploid ('Celina') and the triploid ('Ingeborg') pear cultivars under specific Norwegian climatic conditions. For this purpose, flowers were collected at the beginning of flowering, and on the third, sixth, ninth, and twelfth days after the beginning of this phenophase for two consecutive years. Ovaries were dehydrated, embedded in paraffin wax, sectioned, stained, and observed under the light microscope. In the analyzed cultivars, results showed different tendencies in embryo sac development and degradation processes, in both experimental years, which is probably due to the genetic background of the examined cultivars. Also, fertilization success and fruit set were higher in the second year of study due to the higher average temperature during the flowering period. Diploid cultivar 'Celina' showed much better adaptation to high temperatures in relation to triploid cultivar 'Ingeborg'.

Anatomical and histological characteristics of the lungs in the ground squirrel (Spermophilus citellus).

The aim of this work was to study the topography, morphology, vascularisation, histology and innervation of the lungs in the ground squirrel (Spermophilus citellus) and compare these data with those concerning the rat, mole rat, rabbit and mouse. The research was carried out on 15 animals. It was revealed that the right lung has four lobes (cranial, middle, caudal and accessory lobes), while the left lung is not divided into segments. The functional vessels are a. pulmonalis dextra et sinistra and vv. pulmonales (5-6), while the nutritive vessels of the lungs are a. bronchoesophagea dextra and v. bronchoesophagea dextra. Histological tissue sections of the lungs revealed that the wall of terminal bronchioles contains no cartilage and the mucosal epithelium is pseudostratified, cubic and ciliated. Clara cells (club cells, bronchiolar exocrine cells) are present but have no cilia. The lung alveolar diameter is 37 µm on average, and the thickness of the alveolar wall and the interalveolar septa is 1.38 µm. Destruction of the alveolar walls, accumulation of erythrocytes in the capillaries of alveolar septa and destruction of the cytolemma of the capillary endothelium were detected. In addition, connective tissue fibres and peripheral nerves were detected by silver impregnation.

[Digital morphometric study of the extrasulcal surface of the cingulate gyrus in man].

INTRODUCTION: The frequency of different morphological types and extrasulcal (visible) surface area of the cingulate gyrus, were measured and analysed in order to obtain more precise data about morphology, right/left and sex differences in the human brain. MATERIAL AND METHODS: The study included 42 brains (84 hemispheres) from persons of both sexes and of different age (26 males, 16 females, 20-65 years old), without neuropathological changes. After fixation in 10% formaline (3-4 weeks) and removal of meninges the brains were photographed under standard conditions by digital camera. Following determination of morphological type, regions of interest of cingulate gyrus were determined in stereotactic system system of coordinates and the extrasulcal surface was measured by digital AutoCAD planimetry. RESULTS AND DISCUSSION: Three basic morphological types of cingulate gyrus were found: the continuous type (34.5%), segmented type (35.7%) and double paralel type (29.8%). There was no statistically significant difference in the frequency of morphological types related to the side (right/left) or sex (p 0.05). The area of extrasulcal cortex of cingulate gyrus was statistically significantly (p < 0.05) larger on the left hemispheres (for 1.13 cm) than on the right (left: 14.58 cm; right: 13.45 cnm. 7he extrasulcal surface of the left cingulate gyrus was significantly larger (p 0 .05) in males (males 15.9 cm; females - 13.6 cm), while for the right cingulate gyrus this difference was not significant. CONCLUSION: Morphometry indicated sex and right/left differences of extrasulcal surface area of the human cingulate gyrus. However, the morphological analysis itself did not indicate corresponding differences, suggesting complexity of the problem of sex dimorphism and of right/left asymmetries in the domain of limbic cortex.

[Cytoarchitecture of the human paraventricular hypothalamic nucleus].

INTRODUCTION: The significance of this research in terms of structure and biochemical processes in PVN contributes to further understanding of vital physiological processes from delivery and stress to delicate chemical processes that keep the hypothalamo-hypophysial axis in balance. CONCLUSION: Comparative studies of the human hypothalamus with the hypothalamus of other mammals enable further research, especially pharmacological and physiological ones. These are made possible with the aid of highly sophisticated equipment for examination of neurophysiological features of the brain.